Field of the Invention
The present invention relates to a food intake regulating agent containing 3 kinds of amino acids: threonine, methionine and tryptophan. More particularly, the present invention relates to a food intake regulating agent useful for the prophylaxis or improvement of undernutrition due to decreased appetite, lifestyle-related diseases due to overeating and the like.
Brief Description of the Related Art
In the body, information is collected in the brain through various hormones, cytokines, low molecules, neural connection and the like, and homeostasis is maintained by
1. enhancing or decreasing the appetite over a long term or short term
2. changing the state of metabolism
3. changing the amount of motor activity
(See Science 2003 Vol. 299, No. 5608, pp. 846-849).
It is also known that people gain or lose weight based on the balance between intake calorie from food and calorie consumption by basal metabolism and exercise.
Obesity is developed by a disturbed balance of the above-mentioned homeostasis and calorie consumption, and produces many patients with lifestyle-related diseases such as hypertension, diabetes, hyperlipidemia and the like and people at risk thereof. Food consumption is increasing on a global scale, the obese individuals are still increasing, and prophylaxis or improvement of obesity has been desired.
As a substance that regulates, particularly suppresses, food intake, mazindol in amphetamines is put to practical use as a pharmaceutical product. However, the use thereof is limited to highly obese individuals in view of the direct action of mazindol on the central nervous system and the risk of addiction, dependency and the like. Thus, a safe product that suppresses overeating and prevents obesity has been desired.
On the other hand, elderly people have difficulty in maintaining homeostasis and fall in an undernutrition state due to, for example, a decrease in digestion ability, chewing ability, swallowing ability, exercise capacity, sense of taste, sense of smell and vision, low appetite resulting from change of preference and unbalanced diet because of an influence of disease and drugs. Consequently, they cannot lead a comfortable daily life and suffer from low quality of life (hereinafter to be referred to as QOL) of patients, thus posing a problem.
In addition, cancer patients, patients in an undernutrition state from anorexia due to the side effects of anti-cancer agents and the like, who cannot ingest sufficient nutrition, patients showing insufficient oral ingestion due to anorexia and stress caused by a disease and the like, the above-mentioned elderly people with unsatisfactory nutrition condition and the like may fall under Protein-Energy Malnutrition (PEM) which is undernutrition associated with lack of energy, thus problematically progressing into exacerbated nutrition conditions. However, an effective treatment method has not been established.
As a method for the prophylaxis or treatment of cachexia and anorexia, use of branched chain amino acids such as valine and isoleucine and a small amount of tryptophan is described. However, simultaneous use of antioxidant components such as ω-6 fatty acid, ω-3 fatty acid, β-carotene and the like is essential (See JP-A-11-508282).
There is no report on the improvement of anorexia by free amino acid alone, particularly methionine or threonine, as an essential component.
An appetite control agent containing St. John's wort and an amino acid composed of at least one kind from tryptophan, phenylalanine, arginine, glutamine, histidine, methionine and tyrosine is described (See JP-A-2006-22072).
However, there is no report on the suppression of appetite by a free amino acid alone, particularly threonine as an essential component.